Stair



March 20, 1934. K. BAUER 1,951,895

STAIR Filed July 18. 1932 2 Sheeis-Shget 1 March 20, 1934. BAUER 1 ,951,895

STAIR Filed July 18, 1932 2 Sheets-Sheet 2 Ewe/750w:

Karl Bauer Patented Mar. 20, 1934 UNITED STATES PATENT FFICE Application July 18, 1932, Serial No. 623,208 In Germany August 19, 1931 Claims.

My invention relates to stairs. It is an object of my invention to provide a stair which is selfsupporting, i. e., is not supported on a separate bearing structure in the usual manner. To this 5 end I provide steps and ties inserted in the step structure for supporting the steps, which are connected to the structure by binding matter such as mortar, concrete or the like, so that the steps, with their ties, replace the normally required separate bearing structure.

I may arrange the ties transversely to the steps, insert them in passages between, or holes in, the steps, connect them to the steps by embedding them in binding matter, and anchor them in a side wall if the stair is of the cantilever type, or in both side walls, if such are provided. Or I may anchor the ties in landings at the upper and lower ends of each fiight of steps so that they extend in the longitudinal direction 2.0 of the stair, and embed the ties in passages or holes in the manner described.

According to my invention, I may use natural or artificial stone, glass, concrete or any other material for the steps of my stair, or for the units or stones from which the steps are built up, without requiring a separate bearing structure. Self-supporting stairs of artificial stone are prohibited on account of the fire risk, and stairs having steps of individual stones were heretofore impracticable without a, bearing structure.

The difiiculties which were encountered with materials of the kind referred to, i. e. natural stone, artificial stone, glass, etc., because they cannot be connected directly to ties, are eliminated according to my invention and a self-supporting stair is provided in which the steps themselves replace the bearing structure.

In the drawings aflixed to this specification and forming part thereof stairs embodying my invention are illustrated diagrammatically by way of example.

In the drawings Fig. 1 is a perspective illustration, partly broken open, showing a cantilever stair with 4 transverse ties inserted in passages formed by two adjacent steps,

Fig. 2 is a section on the line II--II in Fig. 1,

Fig. 3 is a section on the line IIIIII in Fig. 2,

Fig. 4 is a perspective illustration partly broken open, showing a cantilever stair having hollow steps and transverse ties inserted in their holes,

Fig. 5 is a perspective illustration, partly broken open, of a stair which is connected to landings at its upper and lower ends, with steps 5.5 abutted by inclined faces at their edges, with recessed sides and longitudinal ties inserted in single block of suitable material but here the steps are shown as built up from units or stones 5 connected by longitudinal joints 6 at their sides. The stones 5 have holes 28 for the reception of solid or hollow dowels 7, with the exception of the outermost stone which has a recess 30 instead of a hole 28. The dowels '7 serve for distributing the load.

The steps, or the units or stones 5 from which they are built up, are stepped at their mating edges, each stone having a plain angular stepped portion 8' at its lower, and a Z-shaped stepped portion 10, 11, 12, 13 at its upper edge, which together form a passage extending transversely to the stair. The lower faces 14 of the stones in the upper step 4 extend slightly down beyond the upper edge 10 of the Z-portion in the mating stone of the lower step 3, and the riser portions 15 of the upper step are set back from the edge 13 at the upper end or" the Z-portion, so that a joint 1'7 is formed between each two steps.

Inserted in the passage formed by the stepped portions 8, 9 and 1013 is a tie 18 which in the case of the cantilever stair illustrated, is bent into a hook 19 at its inner end. The hook is inserted in a hole of the side wall 1 and held by binding matter 20. The outer end of the tie is bent into a loop 21 which preferably extends to about the centre of the outermost stone. If two side walls are provided the ties 18 are alternately in the passages, and the ties 18 are completely embedded in their passages.

Preferably the binding matter or mortar in the joints 6 is connected to the ties by suitable insertions of steel wire or the like, particularly in wide cantilever stairs.

23 are suitable insertions 7' yrs which are preferably shaped substantially like the letter G. One end 24 of each insertion is straight and inserted in a hole of the tie 18, a U-shaped bracket 25 being preferably provided at the connection for increasing its area. The other end of the insertion is a hook 26 so that the insertions have a more effective grip on the binding matter in the joints 6 against the forces which act on the tread of the steps and tend to turn them.

Referring now to Fig. 4, the ties 18, with their hooks 19 and their loops 21, are provided as described with reference to Figs. 1 to 3, but in this instance the steps are built up from stones 27 each having a pair of parallel holes 28, and a tie 18 is inserted in each hole 23 and embedded in binding matter 22. In a stair of the cantilever type as shown, the outermost stone of each step has a pair of recesses 30 instead of a single recess as in Figs. 1 to 3, as shown for the upper step 4, instead of the holes 28. The binding matter 22 from the two holes 28 in the next inner stone penetrates into the two recesses 35. If two side walls 1 are provided the ties 18 may be equipped alternately with hooks l9 and loops 21 at opposite ends, or with hooks 19 at both ends, as described for the stair illustrated in Figs. 1 to 3. The insertions 23 might be provided as illustrated in Figs. 1 to 3 but in the present instance they are replaced by straight wires 31 in holes of the ties 18 and reinforced by the brackets 25, as described, because the turning forces are absorbed by the two ties 18 per tread. As in this type of stair the ties are inserted in the holes 28 of the stones themselves, it is not necessary to provide the stepping at their edges for forming the passages in which the ties 18 are embedded as in Figs. 1 to 3, but the joint 1'7 is formed by plain angular steps 8, 9 in the mating edges of the stones.

Referring now to Fig. 5, this is a stair of the type in which ties 32 are arranged longitudinally to the flight of steps, and anchored to landings or the like (not shown) at their upper and lower ends. The stones 33 of the steps are equipped with abutting faces 34 at their upper and lower edges, the faces being arranged at right angles to the axes of the ties 32 and forming the joint 1'7. In the present instance, the sides of the stones 33 are recessed at 35 between the two abutting faces 34 of each stone, a tie 32 being arranged in each passage formed by two recesses and embedded in binding matter 36. Instead of being recessed, the stones might have longitudinal holes (not shown) for the reception of the ties 32. 37 is a U-shaped wire insertion in the joints 17 by which the load on the ties 32 is distributed. The binding matter fills in the passages or holes between or in the stones, and the joints 6 and 17.

Referring now to Fig. 6, 38 are stones of L-section for the steps of a cantilever stair, each stone having a riser portion 39 and a tread portion 40. The stones have holes which here are shown in triangular arrangement, 41, 42 and 43, the hole 41 being in the riser portion 39 and the hole 43 being in the tread portion 40. Ties 18 are inserted in the holes and embedded in binding matter 22. Preferably ties are inserted only in the holes 41 and 43 at the hypothenuses of the triangles 41, 42, 43 for obvious reasons, but if desired, a tie 18 may also be inserted in the hole 42. The mating faces at the joints 17 are here shown flat and a tie 18 is inserted in the joint 17. However, the mating faces might also be stepped like the edges of the stones illustrated in Figs.

1 to 3 so as to form a passage for the tie 18. If the stair is not of the cantilever type, the ties may be modified as described with reference to Figs. 1 to 3. A tie 18 in the joint 17 may be sufficient for supporting the steps, so that the ties in the holes 41, 43 are dispensed with.

As mentioned, any suitable material may be used for the steps or their units. The stair illustrated in Figs. 1 and 3 is particularly designed for steps of natural stone or glass. The steps 3, 4 might be made of a single block each but preferably are subdivided into the units or stones 5, as shown, the stones being comparatively thin for affording better safety against fire risk. The tie illustrated in Fig. 4 is particularly designed for steps of earthenware, slag stone and the like, which normally are not made as blocks but as individual stones or bricks. Obviously, however, I am not limited to any particular material and a material which is suitable for the stair in Fig. 1, might also be used for the stair in Figs. 1 to 3, and vice versa. The stair illustrated in Fig. 5 may be made of any material while the stair i1- lustrated in Fig. 6 is preferably made of the materials which are suitable for the stair illustrated in'Fig. 4.

Insertions such as 23, Figs. 1 to 3, or 31, Fig. 4, may obviously be provided also in those types of stairs for which they have not been illustrated.

If the forces tending to turn the steps under the load on their treads are not absorbed at two points as in Figs. 4 and 6, or throughout the length of the stones, as in Fig. 5, the insertions are preferably made as shown in Figs. 1 to 3, with the hooks 26 in the region of the lower step 3, which affords a firm hold against the turning forces. In other cases the straight insertions 31, Fig. 4, are sufficient, or insertions may be dispensed with altogether.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

In the claims affixed to this specification no,

selection of any particular modification of the invention is intended to the exclusion of other modifications thereof and the right to subsequently make claim to any modification not covered by these claims is expressly reserved.

I claim:

1. A stair of the cantilever type comprising a side wall, steps, transverse ties anchored in the side wall and, a hook at one end of each tie with which it is inserted in the side wall and embedded in binding matter, and a loop at the other end of the tie, the tie and the loop being inserted in the step structure and embedded in binding matter.

2. A stair of the cantilever type comprising a side wall, steps built up from units, transverse ties anchored in the side wall and, a hook at one end of each tie with which it is inserted in the side wall and embedded in binding matter, a loop at the other end of the tie, the tie and the loop being inserted in the step structure and embedded in binding matter, and an insertion in the joint between each two units which is connected to the tie.

3. A stair of the cantilever type comprising a.

loop at the other end of the tie, the tie and theloop being inserted in the step structure and embedded in binding matter, an insertion in the joint between each two units which is connected to the tie, and a hook at one end of said insertion.

4. A stair of the cantilever type comprising a side wall, steps built up from units, transverse ties anchored in the side wall and, a hook at one end of each tie with which it is inserted in the side wall and embedded in binding matter, a loop at the other end of the tie, the tie and the loop being inserted in the step structure and embedded in binding matter, an insertion in the joint between each two units which is connected to the tie, and a bracket placed on the tie for increasing the area of the connection.

5. A stair of the cantilever type comprising a side wall, steps built up from units, transverse ties anchored in the side wall and, a hook at one end of each tie with which it is inserted in the side wall and embedded in binding matter, a loop at the other end of the tie, the tie and the loop being inserted in the step structure and embedded in binding matter an insertion in the joint between each two units which is connected to the tie, a straight portion forming part of said insertion and positioned in that portion of the joint which is in the region of an upper step, and a hook forming part of said insertion and positioned in that portion of the joint which is in the region of the lower step.

KARL BAUER. 

